CVE-2026-33976Public exploitNetwork attack vector

Desktop RCE via stored Web Clipper XSS

Published Mar 27, 2026 · Updated Mar 27, 2026

Stored XSS in Streetwriters Notesnook before 3.3.11 on Web/Desktop allows remote attackers to execute code in the desktop app. The clipper copies unfiltered root-element attributes into stored clip HTML, which the renderer passes to contentDocument.write in a same-origin, unsandboxed iframe. Exploitation requires the victim to save a complete clip from an attacker-controlled page and later open it; event handlers run in the Notesnook origin, and Electron's enabled Node integration grants desktop code execution.

CVSS severity9.6
Critical
EPSS probability0.71%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Stored XSS in Streetwriters Notesnook before 3.3.11 on Web/Desktop allows remote attackers to execute code in the desktop app. The clipper copies unfiltered root-element attributes into stored clip HTML, which the renderer passes to contentDocument.write in a same-origin, unsandboxed iframe. Exploitation requires the victim to save a complete clip from an attacker-controlled page and later open it; event handlers run in the Notesnook origin, and Electron's enabled Node integration grants desktop code execution.

The record

CVE
CVE-2026-33976
Published
Mar 27, 2026
Updated
Mar 27, 2026
Vendor
Streetwriters
Product
Notesnook
Classifications
CWE-94, CWE-79, T1204.001
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Mar 27, 2026CVE publishedPublication date reported by the CVE source.
  2. Mar 27, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

Compare your product and version with the public record. A matching version still requires validation against your environment.

Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=< 3.3.11
  2. Affected versionversion=< 3.3.17

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Streetwriters · Notesnookversion=< 3.3.11; version=< 3.3.17

Published CVSS scores

9.6GitHub, Inc.CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-94Improper Control of Generation of Code ('Code Injection')
CWE-79Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
T1204.001Malicious Link

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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